Related Experiment Videos
Storage temperature effect on the stability of morphine and codeine in urine
1Graduate Institute of Pharmaceutical Sciences, Taipei Medical College, Taiwan, Republic of China.
Journal of Analytical Toxicology
|September 1, 1995
Summary
Urine sample stability for morphine and codeine is affected by storage temperature. Concentrations of total morphine and codeine decrease over time, while free forms increase, especially at room temperature.
Area of Science:
- Forensic Toxicology
- Analytical Chemistry
- Pharmacology
Background:
- Accurate drug testing relies on the stability of analytes in biological samples.
- Understanding the degradation patterns of morphine and codeine in urine is crucial for interpreting drug test results.
Purpose of the Study:
- To investigate the stability of total and free morphine and codeine in urine samples stored under various temperature conditions over an 11-month period.
- To determine the impact of room, refrigerator, and freezer temperatures on the concentration of these opioids in urine.
Main Methods:
- Urine samples from six individuals were stored without preservatives at room, refrigerator, and freezer temperatures.
- Samples were analyzed at 30-day intervals for 11 months to quantify total morphine, total codeine, free morphine, and free codeine.
Main Results:
- Total morphine and codeine concentrations decreased across all storage conditions, with decreases ranging from 10-40% in refrigerated and frozen samples.
- Free morphine and codeine concentrations generally increased, particularly in room temperature samples, exhibiting varied patterns.
- Room temperature storage showed significant decreases in total morphine in some samples and variable patterns for free morphine.
Conclusions:
- Morphine and codeine concentrations in urine are not stable and degrade over time, influenced by storage temperature.
- Refrigeration and freezing mitigate degradation of total morphine and codeine but do not prevent it entirely.
- The observed increases in free morphine and codeine concentrations highlight the complexity of analyte stability and potential implications for drug testing accuracy.